🧩 PS – Polystyrene
(Rigid, glossy, and easy-to-process material used in caps, grilles, consoles, and car interior elements, but with low impact resistance. Can be thermally welded under controlled conditions.)
🔹 What is PS
PS (Polystyrene) is an amorphous thermoplastic obtained from the polymerization of styrene ($C_8H_8$).
It is a rigid material, either transparent or opaque, with a glossy surface and low density. In the automotive industry, PS is found in interior caps, brackets, grilles, and dashboard parts, sometimes as part of tougher blends (e.g., ABS, HIPS). It is chosen for decorative and technical applications where high mechanical stress is not a factor.
🔧 Composition
- Styrene ($C_8H_8$) – 100 % (pure polymer).
- Density: 1.04–1.06 g/cm³.
- Melting Point: ≈ 200 °C.
- Shore D Hardness: 70–80.
- Classification: PS-crystal (rigid) or HIPS (High Impact, modified with butadiene).
🚗 Where PS is used in the automotive industry
| Component | Example parts | Observations |
| Car Interior | Caps, grilles, handles, frames | Glossy look, easy to process |
| Housings / Supports | Decorative components, diffusers | Lightweight, affordable, rigid |
| Instruments / Panels | Inserts, plates, badges | Dimensionally stable, high gloss |
| DIY / Aftermarket | Custom caps | Easily painted or bonded |
🔧 Welding Temperature and Methods
| Method | Optimal Temperature | Observations |
| Hot Air | 220 – 240 °C | Welding possible, requires careful heating |
| Heat Plate (Mirror) | 210 – 230 °C | Aesthetic joint, risk of warping |
| Manual Extrusion | 200 – 220 °C | Rarely used (fast melting) |
🔩 What to Weld PS With (Material Compatibility)
Since PS is a styrenic material, it only welds with materials from the same family: PS, HIPS, SAN, and ABS (in some cases).
✅ Compatible:
- PS ↔ PS / HIPS – ideal combination.
- PS ↔ SAN / ABS – partially compatible (only if styrene content is high).
❌ Incompatible:
- PP, PE, TPO, PA, PC – different structures and melting points.
💡 ReplastMD Recommendation:
Use PS or ABS rods (for blends) at a temperature of 230–240 °C. Heat uniformly and apply low pressure to avoid cracking. You can further reinforce the welded area by applying a thin layer of styrenic adhesive.
🏭 Manufacturers and Trade Names
- INEOS Styrolution: Styron®, Polystyrol®
- BASF: Polystyrol®, Terlux®
- TotalEnergies: Crystal PS®
- SABIC: PS Resin
🧠 How to Identify PS
- Engraved marking: >PS<, >HIPS<, >PS-HI<, >PS-C<.
- Glossy surface, rigid, brittle in the cold.
- Yellow-blue flame, sweetish (styrenic) smell.
- Softens at ≈ 220 °C without bubbling.
- When breaking, it produces a sharp, snapping sound.
🛠️ PS Welding at ReplastMD:
At our service center in Chisinau (Ciocana sector), ReplastMD performs professional PS welding and restoration for:
- car interior caps, frames, and elements;
- decorative parts, panels, and consoles;
- repairing broken mounts or shattered corners.